What is the meaning of ер?

earth

land

land; real estate or landed property

ground; soil

locality, place

yer (Slavic languages)

man

hero

husband

saddle

earth

1. Earth

Earth

ground

territory

place

space

saddle

ground, earth, land

yer (Slavic languages)

ninety

common, usual

at all

letter "ъ", now called твёрдый знак (tvjórdyj znak)

Source: wiktionary.org